A comparative transcriptomics analysis reveals ethylene glycol derivatives of squalene ameliorate excessive lipogenesis and inflammatory response in 3T3-L1 preadipocytes

Squalene (SQ) is a natural compound with anti-inflammatory, anti-cancer, and anti-oxidant effects, but due to its low solubility, its biological properties have been greatly underestimated. This study aims to explore the differences in gene expression patterns of four newly synthesized amphipathic ethylene glycol (EG) derivatives of SQ by whole-genome transcriptomics analysis using DNA microarray to examine the mRNA expression profile of adipocytes differentiated from 3T3-L1 cells treated with SQ and its EG derivatives. Enrichment analyses of the transcriptional data showed that compared with SQ, its EG derivatives exerted different, in most cases desirable, biological responses. EG derivatives showed increased enrichment of mitochondrial functions, lipid and glucose metabolism, and inflammatory response. Mono-, di-, and tetra-SQ showed higher enrichment of the cellular component-ribosome. Histological staining showed EG derivatives prevented excessive lipid accumulation. Additionally, mitochondrial transcription factors showed upregulation in tetra-SQ-treated cells. Notably, EG derivatives showed better anti-inflammatory effects. Further, gene-disease association analysis predicted substantial improvement in the bioactivities of SQ derivatives in metabolic diseases. Cluster analyses revealed di- and tetra-SQ had more functional similarities than others, reflected in their scanning electron microscopy images; both di- and tetra-SQ self-organized into similar sizes and shapes of vesicles, subsequently improving their cation binding activities. Protein-protein interaction networks further revealed that cation binding activity might explain a major part, if not all, of the differences observed in functional analyses. Altogether, the addition of EG derivatives may improve the biological responses of SQ and thus may enhance its health-promoting potential.

A Rare Olive Compound Oleacein Improves Lipid and Glucose Metabolism, and Inflammatory Functions: A Comprehensive Whole-Genome Transcriptomics Analysis in Adipocytes Differentiated from Healthy and Diabetic Adipose Stem Cells

Oleacein (OLE), a rare natural compound found in unfiltered extra virgin olive oil, has been shown to have anti-inflammatory and anti-obesity properties. However, little is known regarding the mechanisms by which OLE influences metabolic processes linked to disease targets, particularly in the context of lipid metabolism. In the present study, we conducted whole-genome DNA microarray analyses in adipocytes differentiated from human adipose-derived stem cells (hASCs) and diabetic hASCs (d-hASCs) to examine the effects of OLE on modulating metabolic pathways. We found that OLE significantly inhibited lipid formation in adipocytes differentiated from both sources. In addition, microarray analysis demonstrated that OLE treatment could significantly downregulate lipid-metabolism-related genes and modulate glucose metabolism in both adipocyte groups. Transcription factor enrichment and protein-protein interaction (PPI) analyses identified potential regulatory gene targets. We also found that OLE treatment enhanced the anti-inflammatory properties in adipocytes. Our study findings suggest that OLE exhibits potential benefits in improving lipid and glucose metabolism, thus holding promise for its application in the management of metabolic disorders.

Abstract C068: Isorhamnetin restricts cancer-associated fibroblasts (CAFs) phenotypic plasticity, poising them towards tumor-restraining myCAFs: Potential use of isorhamnetin as neoadjuvant in pancreatic ductal adenocarcinoma (PDAC)

Pancreatic ductal adenocarcinoma (PDAC) is the deadliest cancer due lack of early diagnosis and inherent refractory to traditional chemo- and even novel immune-therapies. PDAC is marked by its extensive desmoplastic stroma containing extracellular matrix (ECM), vasculature and most importantly cancer-associated fibroblasts (CAFs). CAFs that exist in heterogenous subtypes are responsible for shaping PDAC tumor microenvironment being the main source of: ECM deposition leading up to desmoplasia that hampers the efficacy of various therapeutics, as well as diverse cytokines and growth factors that promote the growth of cancer cells and the shift towards dedifferentiated and invasive phenotype and contribute towards immune suppressive microenvironment. Thus, modulating CAFs phenotype is an attractive mean to increase the efficacy of therapies targeting PDAC cells. Here we assessed the potential therapeutic benefits of Isorhamnetin, a flavonoid previously shown to exert anti-proliferative, anti-fibrotic and anti-inflammatory effect in various cancer types, to modulates PDAC microenvironment by characterizing Isorhamnetin effect on human PDAC-derived CAFs. Isorhamnetin inhibited CAFs proliferation, induced apoptosis, and cell cycle arrest by impairing mitochondrial health. Importantly, isorhamnetin attenuates the expression of inflammatory CAFs (iCAFs) signature including IL1A, IL6, LIF, CXCL1 and promotes phenotype shift towards myofibroblasts (myCAFs)-as evident in higher level of αSMA positive CAFs. Our results demonstrate antiproliferative effect of isorhamnetin on human PDAC-derived CAFs and a phenotype switch from iCAFs to myCAFs and warrant further investigation for its use in combinatorial therapy that target both the cancer and the tumor microenvironment as a whole.

Citation Format: Munkhzul Ganbold, Pakavarin Louphrasitthiphol, Yoshihiro Miyazaki, Tatsuya Oda, Kenichi Tominaga, Hiroko Isoda. Isorhamnetin restricts cancer-associated fibroblasts (CAFs) phenotypic plasticity, poising them towards tumor-restraining myCAFs: Potential use of isorhamnetin as neoadjuvant in pancreatic ductal adenocarcinoma (PDAC) [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C068.

New Amphiphilic Squalene Derivative Improves Metabolism of Adipocytes Differentiated From Diabetic Adipose-Derived Stem Cells and Prevents Excessive Lipogenesis

Squalene (Sq) is a natural compound, found in various plant oils, algae, and larger quantity in deep-sea shark liver. It is also known as an intermediate of cholesterol synthesis in plants and animals including humans. Although evidences demonstrated its antioxidant, anticancer, hypolipidemic, and hepatoprotective and cardioprotective effects, its biological effects in cellular function might have been underestimated because of the water-insoluble property. To overcome this hydrophobicity, we synthesized new amphiphilic Sq derivative (HH-Sq). On the other hand, adipose-derived stem cells (ASCs) are a valuable source in regenerative medicine for its ease of accessibility and multilineage differentiation potential. Nevertheless, impaired cellular functions of ASCs derived from diabetic donor have still been debated controversially. In this study, we explored the effect of the HH-Sq in comparison to Sq on the adipocyte differentiation of ASCs obtained from subjects with type 2 diabetes. Gene expression profile by microarray analysis at 14 days of adipogenic differentiation revealed that HH-Sq induced more genes involved in intracellular signaling processes, whereas Sq activated more transmembrane receptor pathway-related genes. In addition, more important number of down-regulated and up-regulated genes by Sq and HH-Sq were not overlapped, suggesting the compounds might not only have difference in their chemical property but also potentially exert different biological effects. Both Sq and HH-Sq improved metabolism of adipocytes by enhancing genes associated with energy homeostasis and insulin sensitivity, SIRT1, PRKAA2, and IRS1. Interestingly, Sq increased significantly early adipogenic markers and lipogenic gene expression such as PPARG, SREBF1, and CEBPA, but not HH-Sq. As a consequence, smaller and fewer lipid droplet formation was observed in HH-Sq-treated adipocytes. Based on our findings, we report that both Sq and HH-Sq improved adipocyte metabolism, but only HH-Sq prevented excessive lipogenesis without abrogating adipocyte differentiation. The beneficial effect of HH-Sq provides an importance of synthesized derivatives from a natural compound with therapeutic potentials in the application of cell therapies.

Isorhamnetin Alleviates Steatosis and Fibrosis in Mice with Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH) is the most severe and progressive form of nonalcoholic fatty liver disease (NAFLD), which can lead to life-threatening conditions, however, there is still no approved drug for the treatment of NASH. In this study we used human-like NASH mouse model and treated orally with isorhamnetin at a dose of 50 mg/kg to analyze the effect of isorhamnetin on the progression of NASH. NASH-induced mice represented severe steatosis with inflammation, and fibrosis in liver accompanied with high level of liver injury markers in serum. Isorhamnetin treatment reduced intrahepatic lipid accumulation and TG content by inhibiting de novo lipogenic pathway in NASH-induced mice. Consistent with this, isorhamnetin-treated NASH mice showed improved liver injury markers, reduced collagen deposition as well as decreased gene expression of fibrogenic markers. Taken together, here we showed for the first time that synthesized isorhamnetin alleviates pathologic features of NASH and thus can potentially contribute to NASH drug development.

The nuclear retinoid-related orphan receptor-α regulates adipose tissue glyceroneogenesis in addition to hepatic gluconeogenesis

Circadian rhythms have an essential role in feeding behavior and metabolism. RORα is a nuclear receptor involved in the interface of the circadian system and metabolism. The adipocyte glyceroneogenesis pathway derives free fatty acids (FFA) liberated by lipolysis to reesterification into triglycerides, thus regulating FFA homeostasis and fat mass. Glyceroneogenesis shares with hepatic gluconeogenesis the key enzyme phosphoenolpyruvate carboxykinase c (PEPCKc), whose gene is a RORα target in the liver. RORα-deficient mice (staggerer, ROR(sg/sg)) have been shown to exhibit a lean phenotype and fasting hypoglycemia for unsolved reasons. In the present study, we investigated whether adipocyte glyceroneogenesis might also be a target pathway of RORα, and we further evaluated the role of RORα in hepatocyte gluconeogenesis. In vivo investigations comparing ROR(sg/sg) mice with their wild-type (WT) littermates under fasting conditions demonstrated that, in the absence of RORα, the release of FFA into the bloodstream was altered and the rise in glycemia in response to pyruvate reduced. The functional analysis of each pathway, performed in adipose tissue or liver explants, confirmed the impairment of adipocyte glyceroneogenesis and liver gluconeogenesis in the ROR(sg/sg) mice; these reductions of FFA reesterification or glucose production were associated with decreases in PEPCKc mRNA and protein levels. Treatment of explants with RORα agonist or antagonist enhanced or inhibited these pathways, respectively, in tissues isolated from WT but not ROR(sg/sg) mice. Our results indicated that both adipocyte glyceroneogenesis and hepatocyte gluconeogenesis were regulated by RORα. This study demonstrates the physiological function of RORα in regulating both glucose and FFA homeostasis.